Abstract: Liquid crystal display in which a twisted nematic type liquid crystal cell is disposed between a linear polarizer and a guest-host type liquid crystal cell with homogeneous alignment and an electric field is selectively applied externally to arbitrary liquid crystal layers. Electro-optical control of inverted display of positive-to-negative images, complicated figure display and multi-color display is made possible.

Abstract: A nematic liquid crystal with positive dielectric anisotropy and a nematic liquid crystal with negative dielectric anisotropy are mixed such that the mixture is given a positive dielectric anisotropy and whenever any kind of pleochroic dye is dissolved therein, can effectively utilize its absorption anisotropy for display performances. A clear color-to-color contrast display is provided by employing the mixed liquid crystal added with pluralkinds of dyes of which at least one is a pleochroic dye and at least two are different in hue and in preformance characteristics of display device.

Abstract: An electro-optical element comprising a nematic liquid crystal composition and at least one compound represented by the formula: ##SPC1##Wherein R is an alkyl radical having from 4 to 20 carbon atoms.Said compounds are pleochroic dyes having a special function which differs from hitherto known dyes in their interaction with nematic liquid crystal molecules. The electro-optical element makes it possible to obtain a liquid crystal display device which exhibits the desired figure in color differing from background colors.